A technician in the NYPD’s forensics lab has been suspended for allegedly falsifying drug-test results, throwing into question “maybe thousands” of criminal cases — and prompting a panicked meeting yesterday between cops and the city district attorneys.

A Bronx drug trial was even abruptly halted last week because the longtime lab technician, Mariem Megalla, was supposed to testify in that case, sources told The Post.

The NYPD last week sent out an emergency e-mail to the city’s five DAs warning them about the evidence disaster and telling them to examine pending felony case files for evidence tested by her. In all such cases, the NYPD wrote, the evidence will need to be retested to make sure the results are accurate.

Police brass also huddled with DA reps yesterday to discuss how to handle the problem.

“It could potentially be hundreds and maybe thousands of cases that need to be looked at because of how long she’s been in the department,” a source said, citing pending and closed cases.

Megalla, 57, is accused in one case of falsely labeling a sample of suspected drugs as positive for cocaine after it actually tested negative — because she allegedly didn’t want to walk to another part of the building and fill out paperwork to have it tested further, the sources said.

The case involved her testing 84 glassine bags of suspected cocaine. After 38 of the bags tested positive, the 39th came back negative, sources said.

But rather than having it retested, she simply peeled off the positive label from the 38th sample, allegedly slapped it on the 39th and retested the 38th herself, knowing it would come back positive, and got that new label and put it on the 38th sample, sources said.

In another case, she is accused of labeling as positive a crack pipe that had tested negative for drug residue, again to save her time and work, sources said.

“Right now, it looks a lot like either sloppiness or laziness,” one source said.

NYPD spokesman Paul Browne said, “Shortcuts were done in lieu of retesting . . . It’s not acceptable to take these shortcuts.”

Both alleged incidents were uncovered by NYPD quality-control staffers after Megalla performed the initial tests in late April in the department’s drug lab in Jamaica, Queens.

The lab has been plagued by testing scandals in recent years.

The 24-year civilian NYPD veteran now faces probes by the department and the Queens District Attorney’s Office.

Megalla was suspended without pay Friday, the day she was to testify in the Bronx drug trial.

Sources said Megalla tested drugs in about 180 open felony cases this year alone.

Bridget Brennan, the city’s special narcotics prosecutor, said her office was “working with the Police Department and other district attorney’s offices to determine which and how many cases need to have evidence re-tested.”

Reached by The Post at her Queens home yesterday, Megalla cried: “Let them look at my cases! I didn’t do any crime!”

Her lawyer, Benjamin Lieberman, said, “She stands behind the position that she hasn’t done anything wrong, and she’s happy to cooperate with law-enforcement agencies” probing the case.

“The quality of her work has never ever been called into question” before.

The Post in July 2006 revealed that the NYPD was reviewing hundreds of cases dating back eight years because of another veteran lab tech’s “sloppy” and “incompetent” work.